import java.util.Scanner;

    public class 计算圆 {
        public static void main(String[] args) {
            circular();
        }
        public static void circular(){
            Scanner scanner =new Scanner(System.in);
            System.out.println("请输入圆的半径：");
            double r=scanner.nextDouble();
            System.out.println("圆的面积为："+Math.PI*Math.pow(r,2));
            System.out.println("圆的周长为："+2*Math.PI*r);
        }
    }
